Just for a bot of fun...to consider.. A simple system of converting tidal rise and fall to accumulated pressure. Process in brief: Using the tides to pressurize a chamber thus storing potential energy to run an electric turbine over time. The tide rises generating air pressure, that is piped into a pressure vessel via a one way valve. Over time and after the pressure reaches a given point the stored pressure can be bled off to run a turbine. Of course the amount of storing has to exceed the use. [ over an extended time period - the accumulator chamber acting as a buffer to allow for slack and outgoing tides] Only moving parts are the various poppet valves needed... Please Register or Log in to view the hidden image! I wonder if feasibility studies have been carried out on this idea or something similar? Imagine: Millions of these tidal pressure engines , scattered around providing renewable energy at very little cost [ maintenance ] that over an extended period could be used to drive electricity generators. Could be all under ground and eco friendly... The system could also capitalize on the down cycle creating an accumulated low pressure storage.